"Teaching them to obey everything I have commanded you." Mt 28:20a.
"Both the Magisterium of the Church, in the course of a constant tradition, and the moral sense of the faithful have been in no doubt and have firmly maintained that masturbation is an intrinsically and gravely disorded action. "The deliberate use of the Sexual faculty, for whatever reason, outside of marriage is essentially contrary to its purpose." -Article 2352 of the Catechism of the Catholic church.
The subject of masturbation is a frustrating one. Frustrating due to its immanent possibility as habit in the life of all youth, frustrating due to its complete silence in all scriptural testimony, its harsh censure without clear reason in Magisterial policy, its smooth and psuedo-philosophical rejection in Protestant ministries, and its frightening approval from Liberal cronies and amoral doctors. The Christian world has an ethic without reason conerning masturbation and the secular world has no ethic at all. Both positions-in my view- are entirely unhelpful and profoundly irritating. Even more irritating is my complete inability to make any positive contribution to this sexual dilemma.
I doubt that it will do any good to "pray through" the issue, as if one can expect a further objective revelation from God that can be added to his Word. I have tried to do this before. I usually end up getting an experience of complete peace which is later followed by an experience of resurging censure from my conscience. Both are anthropological residue and have no necessary link to the Holy Spirit (especially since both contradict each other!). Attempts to deduce a general sexual ethic from scripture that one can extrapolate from and interpose have usually failed. The fact that masturbation is "self-oriented" is quite a foolish argument. So is going to sleep. So is making a pot of coffee or reading a paperback novel. So is going for a run or making a tasty-as opposed to bland- breakfast. There are far too many things in this world whose ontological value by divine writ are for our enjoyment.
Appeals to the sin of lust are unhelpful. With discipline and resolve of mind the sexuality (whether in intercourse or in self-stimulation) can be cultivated without fantasy or controversial thoughts of the other. It is possible, available and common to express the sexuality without making any recourse at all to any entity.